I have seen many programs consisting of structures like the one below
typedef struct
{
int i;
char k;
} elem;
elem user;
I have seen this many times. Why is it needed so ... |
In C, is there a difference between writing "struct foo" instead of just "foo" if foo is a struct?
For example:
struct sockaddr_in sin;
struct sockaddr *sa;
// Are these two lines equivalent?
sa = (struct ...
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What's the difference between these two declarations, and is one preferred over the other?
typedef struct IOPORT {
GPIO_TypeDef* port;
u16 ...
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Sometimes I see code like this (I hope I remember it correctly):
typedef struct st {
int a; char b;
} *stp;
While the usual pattern that I familiar with, is:
typedef ...
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I have seen source codes always having a typedef for a structure and using the same everywhere instead of using the structure name as "struct sname" etc directly?
What is the reason ... |
Is there any benefit in having never-defined structures in C ?
Example in SQLite source code :
/* struct sqlite3_stmt is never defined */
typedef struct sqlite3_stmt sqlite3_stmt;
And the object is manipulated like so ... |
Both this style:
struct _something
{
...
};
typedef struct _something someting;
and that style:
typedef struct _something
{
...
} something;
are correct typedef declarations in C.
Note that the presence of the structure declaration in the ... |
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Hello there
I am facing a weird problem I have defined I a structure in a C header file:
typedef struct iRecActive{
char iRecSID[32];
unsigned ...
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Are the following equivalent in C?
// #1
struct myStruct {
int id;
char value;
};
typedef struct myStruct Foo;
// #2
typedef struct {
int id;
...
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Why would I want to do this?
typedef struct Frame_s
{
int x;
int y;
int z;
} Frame_t;
Also if I want to create an object what do I use Frame_s or Frame_t?
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I am using structs in my project in this way:
typedef struct
{
int str1_val1;
int str1_val2;
} struct1;
and
typedef struct
{
int str2_val1;
...
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gcc 4.4.4 c89
I have always done the following when using structs to hide the elements in the implementation file.
port.h header file
struct port_tag;
struct port_tag* open_ports(size_t port_id);
void close_ports(struct port_tag *port);
port.c implementation file
#include "port.h"
typedef ...
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Consider the following typedef struct in C:
21:typedef struct source{
22: double ds; //ray step
23: double rx,zx; ...
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In the given code snippet, I expected the error symbol Record not found. But it compiled and ran fine on Visual Studio 2010 Compiler. I ran it as a C program ... |
I want to make my code more easy to read, so i want to replace a big structure set, to something more expresive, but it doesn't compile.
typedef float vec_t;
typedef vec_t vec3_t[3];
typedef ...
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I have a ".c .h" couple.
In the .h I define 2 typedef struct, say TS1 and TS2
Now, one of the member of TS1 is TS2 type.
I'd like to make only TS1 ... |
Can a typedef struct be used without knowing its type?
e.g. There is a module on another embedded microcontroller that expects a struct and the struct is sent from another board and ... |
So my question is multifaceted.
For the purpose of understanding C (not C++) I believe the following code:
struct Foo { int bar; };
creates a custom type that I can use, but ... |
What I've written is:
typedef enum _MyStatus
{
MY_STATUS_OK = 0,
MY_STATUS_GENERAL_ERROR = -1,
} MyStatus;
typedef MyStatus (*MyCallback)(MySettings *settings);
typedef struct _MySettings
{
MyCallback callback;
} MySettings
However, it ... |
I'm working on a small platform abstraction layer that I intend to use as a base for future projects. Originally, I was following the lead of SDL and dynamically allocating a ... |
struct node
{
int coef;
int exp;
struct node *link;
};
typedef struct node *NODE;
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If you remove the typedef the name of your struct type is just 'struct COMPLEX'. You have to set the type of your complex variables to 'struct COMPLEX' instead of just 'COMPLEX'. Why you don't want to use a simple typedef is beyond me. note that in C++ you *can* use 'COMPLEX' instead of 'struct COMPLEX'. kind regards, Jos |
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lyf2iis@gmail.com wrote: typedef struct node *NODEPTR; > struct node { char *item; NODEPTR next; }; > my question is how the compiler can compile this code? the struct haven't define when i use typedef. It doesn't have to be, because (C99, 6.2.5#27): # All pointers to structure types shall have the same representation and # alignment requirements as each other. (And ... |
Hi, guys, In C language manner, we need to put a "struct" token before one struct variable declaration like following. struct Apple { float Price; }; struct Apple apple; Sometime, we would use typedef to simplify the usage. typedef struct _Apple { float Price; } Apple; Apple apple; Now, when we use this manner in C++, it ... |
Guillaume Dargaud wrote: I just saw the following two lines in /usr/include/usb.h and my head is spinning: > struct usb_dev_handle; typedef struct usb_dev_handle usb_dev_handle; It means that both "struct usb_dev_handle" and the typedef "usb_dev_handle" now refer to a struct with a tag of usb_dev_handle, but you don't know what is inside that struct. But it is enough information to declare for ... |
godfatherofsoul@yahoo.com wrote:[color=blue] > I notice that sometimes typedef struct definitions have an additional > "prefix" identifier like so: > > typedef struct prefixName > { > char firstName; > char lastName; > } Name_t; > > What is the rationale for the extra name and what are the implications > of leaving it off?[/color] This is a relic from C, where ... |
lets say I have a header file : struct AAAA { blabla..... }; typedef struct AAAA A; typedef struct BBB { blabla... ..... } B; I try to compile it and get an error message that "AAA" has already been declared in the current scope ! ( And I checked everywhere it is not ! ) What's funny is , that ... |
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#include #include int main() { int i,studnum; typedef struct { int id[10] ; int vath[3]; float tel_vath;} students ; students n; scanf("%d", &studnum); if(studnum<1 || studnum>10) exit(-1); for (i=0;i100) break; for (i=0;i |
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tankState get_State( unsigned short int xMap, unsigned short int yMap, unsigned short int Ammo, unsigned short int Fuel, char* Move, unsigned short int alive1, unsigned short int alive2) { tankState t; t.alive1 = alive1; t.alive2 = alive2; t.Ammo = Ammo; t.Fuel = Fuel; t.xMap = xMap; t.yMap = yMap; t.Move = Move; return t; } |
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An OO approach in C is not tied to class nomenclature, etc. It's pretty straightforward, just simple logic. If you have worked with linked lists before, think about the methodology there: you have a bunch of functions that act on objects. The methods are external to the object in the code, however. So, you want a new_table function: Code: table *new_table ... |
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void alloc_node ( node ** u, unsigned int n ) { *u = ((node)*) malloc(sizeof(node)); if(*u == NULL) { printf("alloc_node: (1) Not enough storage available.\n"); exit(1); } (*u)->n_e = n; (*u)->e = (edge**) malloc(n * sizeof(edge*)); if ((*u)->e == NULL) { printf("alloc_node: (2) Not enough storage available.\n"); exit(1); } } void alloc_edge ( edge** e ) { *e = ((edge)*) malloc(sizeof(edge)); ... |
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I have only been using C for 3 weeks and this is my first post. I have been trying to use typedef and struct to make things more logical, but it's not quite working. Here is the problematic code, first the part that's working and then the new version I am having trouble with: Code: #include #define DECK 52 #define ... |
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Hi, I am doing a little work and I have this. Code: #include #include #define NumberOfStudents 10 struct Student { int studentID; float balanceOwed; float gpa; }; typedef struct Student student; int main( int argc, char **argv ) { int i; int id; int index = -1; bool willGraduate = true; Student student[]={ {10, 0.0, 1.0}, {20, 100.0, 3.0}, ... |
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test.c:7: parse error before "AdQueueNode" test.c:7: warning: no semicolon at end of struct or union test.c:9: warning: data definition has no type or storage class test.c: In function `main': test.c:14: `n' undeclared (first use in this function) test.c:14: (Each undeclared identifier is reported only once test.c:14: for each function it appears in.) |
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-------------------------------------------------------- void test(getnode *ptr); #include typedef struct { int a; int b; } NODE; int main () { NODE getnode; NODE *ptr; printf ("Please enter your num > "); scanf ("%d",&getnode.a); printf ("Please enter your 2nd num > "); scanf ("%d",&ptr->b); printf ("your ans is ... %d and %d\n\n", getnode.a, ptr->b); return 0; } |
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I am trying to incorporate some OpenGL code into my Kylix3 app, and have run across a difficulty not with OpenGL or Kylix, but C of all things. in Kylix, there is the following typedef: typedef struct QWidget__ { int dummy; } *QWidgetH Now, I have a function that returns me a QWidgetH *, and I have another function that needs ... |
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What-ever your preference. As long as you don't intend to publish struct listnode in a public API (ie, more consumers than just yourself or friends who agree with your coding style). Having to type struct whatever is just a pain the anal orifice. The point isn't to hide that fact that it's a struct, the point is to save me from ... |
Anyone know the rationale for using typedef for structs when a struct is itself a typedef? I have seen this in just about every book I have ever read, never with any explanation, yet I know from extensive personal experience that the end result is exactly the same (at least on all compilers from the last 10 years). Is it nothing ... |
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Typedefs in C are not genuinely new types in the same way that say a class is in C++. They are simply aliases for some existing type. Using a typedef in this instance removes the need to explicitly define a tag, and declare each instance with struct ; Instead you have; ; This is less cumbersome, especially ... |
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#include typedef struct{ int iDnum[10]; char Lname[20]; char Fname[20]; }STUDENT; typedef struct{ int cNum[10]; char sTitle[10]; int unit[5]; int fGrad[5]; }SUBJECT; typedef struct{ STUDENT *student; SUBJECT subject; char sem[10]; }RECORD; void add(RECORD *profile); int main(void) { RECORD *record; record=(RECORD*)malloc(sizeof(RECORD)); clrscr(); add(record); getch(); return 0; } void add(RECORD *profile) { int i,j; char m; printf("How many students?---> "); scanf("%d", &i); for(j=0; j |
/* DS1302 RTC Drivers*/ #pragma SMALL // Small memory model #include #include #include #include "delay.h" #include "lcd.h" //#define ResetWD() WDTCON = WDTCON | 0x02 sbit DS1302Sclk = P0^0; sbit DS1302Io = P0^1; sbit DS1302Ce = P0^2; sbit ACC0 = ACC^0; sbit ACC7 = ACC^7; typedef struct __SYSTEMTIME__ { unsigned int Second; unsigned int Minute; unsigned int Hour; unsigned ... |